Relatively few health, finance, and shopping Web sites consistently disclose information such as advertising and sponsorship ties that may affect the credibility of their published material. One example: shopping sites that purport to rank products for buyers in an unbiased way, when companies actually pay for their products to be ranked.

That news, the outcome of an international investigation, is among the findings of a study by Consumers International, an advocacy group of which Consumers Union is a member, and Consumer WebWatch, www.ConsumerWebWatch.org , CU’s initiative to help improve the credibility of information on the Web.

Launched one year ago, Consumer WebWatch publishes research to highlight issues of concern among the Web’s most-trafficked categories, including travel, health information, and search engines. Based on that research, it creates guidelines for Web sites such as standards for advertising disclosure. Those guidelines are used, among other things, to provide the Web site e-Ratings on our site.

Consumer WebWatch is funded by grants from the Pew Charitable Trusts, the John S. and James L. Knight Foundation, and the Open Society Institute.

Other Consumer WebWatch research has found the following:

 Only a small percentage of survey respondents who use search engines said they knew that companies often pay to have their Web pages appear in a search result. Some, such as Google, are more forthcoming about this practice of paid placement and clearly label results for which advertisers pay. Others don’t.

Consumers don’t hold in high regard shopping Web sites that offer products or services for sale. Of the 1,500 adult Internet users who responded to a Consumer WebWatch survey last year, only 29 percent said they trusted shopping sites "most of the time" or "just about always." Most ranked such Web sites dead last on a trustworthiness scale that included the federal government and large corporations.

Though consumers said they were more inclined to trust Web sites with features such as a prominently displayed privacy policy, in practice they were more inclined to judge that a site is reliable based on its layout and other design aspects.

In April, Consumer WebWatch sponsored a leadership conference for Web publishers that examined the importance of basic disclosures. Later this year, the program will investigate search engines. For Consumer WebWatch’s preliminary research on hotel-booking sites, check out www.ConsumerWebWatch.org.